The present invention relates to a coupler which is useful in magnetically or inductively coupling a pair of communication loops, power loops, or combined power and modulated data loops.
Electrical communication systems often comprise a number of interrelated but physically separated subsystems. Data may be communicated from the source terminal to the subsystems, and from the subsystems to the source terminal, by means of electrical conductors carrying voltage variations. The terminal and the subsystems may each have a wire loop or conductor emanating therefrom, and the conductors may be efficiently coupled by means of a coupler. The efficiency of the coupler preferably reaches levels of over 90%. Voltage variations transmitted via the conductors may then communicate data between the source terminal and substations. Further, magnetic coupling allows for easy connecting and unconnecting of the source terminal and the subsystems so that various subsystems or branches may be removed and/or replaced without shutting down the entire system. One example of a communication system using magnetic coupling is U.S. Pat. No. 4,264,827.
In order to magnetically couple insulated conductors, the conductors should be placed in close proximity to each other. Surrounding the coupled conductors with magnetic cores increases induction efficiency. One such application of magnetic couplers for use with electronic communication devices or systems is disclosed in commonly-owned U.S. Pat. app. Ser. No. 08/398,297 filed Mar. 3, 1995 in the name of Frederick et al., hereby incorporated by reference. That application discloses an article information display system using electronically controlled tags. More particularly, an apparatus for displaying the price and name of a product on electronic display tags adjacent to the respective products is disclosed. The system displays information for individual articles, and the displays can be updated from a central location. The application discloses the use of a "clam-shell" coupler to couple a branch distribution loop to a main distribution loop. In this manner, information concerning the article for sale may be communicated from the main terminal to the substations.
Couplers are typically movable from an open position, wherein the core elements are separate and exposed to the environment, to a closed position where the core elements are pressed together and the conductors are contained therein. It is known that debris trapped between the magnetic core elements may lower the efficiency of the coupler. Dirt, dust, or residue from the manufacturing process collected on core elements lowers the effectiveness of the coupler. Accordingly, there exists a need for a coupler which can clean debris off of the exposed core elements to thereby provide intimate contact between the cores. There also exists a need for a coupler which can be quickly and easily operated by a worker on-site to allow convenient connection of conductors.